The field of the invention is that of fiber optic outdoor distribution cables.
Field trials are underway to extend the use of optical fibers from large telecommunication trunk cables to local networks carrying optical fibers to local subscribers, such as individuals or small businesses. Such distribution cables must carry a smaller number of optical fibers than the larger trunk cables and must have the capability to branch off individual optical fibers or optical fiber subunits. Traditionally, routing of smaller communication cables takes place through existing distribution pedestals or other enclosures providing limited internal space. In such enclosures, cables having a smaller minimum bending radius have an advantage over cables having a larger minimum bending radius. The minimum bending radius as used herein is that bending radius through which an optical cable may be flexed over a long period of time without a significant increase in attenuation of signal.
Another requirement of such distribution cables is that they be able to function in outdoor environments. Such environments require means to resist the invasion of water and rodent attacks and further provide protection against tensile forces and blows to the exterior of the cable.